PDSA, the UK's leading veterinary charity, knows how to engage pet lovers (and potential contributors) in conversations all over the social media world. I like the look and easy navigation of the home page, with wonderful photos of pets and links to pet-care info, 'petcasts' (videos), e-newsletter subscription and much, much more. Home page also has quick links to donate or sign up for services.
If you're on Facebook, you can join PDSA's 26,000+ fans, browse the many pet photos (and upload your own), check the calendar for local events near you and donate online if you choose.
Take a look at PDSA's Bebo page--lots of fun for youngsters. Or its YouTube channel. Or its Flickr posts. Or its tweets.
PDSA + social media + pet lovers = savvy marketing.